Improvement in percussion-fuse for explosive shells



UNITED STATES ATENT FFICE.

JOHN F. SHEARMAN, OF BROOKLYN, E. D., NEW YORK.

Specification forming part of Letters Patent No. 5 1,027, dated April17, 1866.

To all whom it may concern:

Be it known that I, JOHN F. SHEARMAN, of Brooklyn, E. D., in the countyof Kings and State of New York, have invented, made, and applied to usea certain new and useful 1mprovement in Projectiles for Ordnance; and Ido hereby declare the following to be a full, clear, and exactdescription of my said invention, reference being had to the annexeddrawings, making part of this specification, where- 111-- Figure l is alongitudinal section of my projectile. Fig. 2 is a side elevation of thesame. Figs. 3 and 4 are views of the rear end of the projectile, andFigs. 5 and 6 are views of the front end of the projectile. In Fig. 5the screwplug is removed.

Similar marks of reference denote the same parts.

Projectiles have heretofore been made with a sliding nipple carrier orhammer held into a screw-sleeve by means of a set-screw, the end ofwhich enters a hole in the side of said slidin g nipple-carrier. In thisconstruction the end of the screw is apt to be out oft'in the suddenrotation ofthe projectile by the rifle-grooves, because the forcenecessary to overcome the inertia and rotate said nipple-carrier isderived alone from the point of the screw. Hence pre' mature explosionssometimes occur from the nipple-carrier being loose in its flight fromthe before-mentioned cause.

The nature of my said invention consists in forming a groove around thenipple-carrier receivin g the point of the retaining-screw, so that theshell may be rotated by the rifle-grooves without the saidnipple-carrier being rotated as the projectile is suddenly started. Ialso make use of two or more nipples carrying percussion-caps to insureexplosion when the projectile strikes; and I introduce a safety-wirebetween the hammer and screw-plu In the drawings, a is the shell of theprojectile, with the central cavity, 12, for the reception of thepowder. 0 is a polygonal base at the back end of the projectile, overwhich is placed the polygonal opening of the ring d, which is formedhollow, as represented, in order that the pressure of the gases when theprojectile isfired may expand the said ring to form a gaseheck, and alsofill the grooves when said projectile is used in a rifled gun.

By having the polygonal projection c slightly undercut or taperingtoward the front of the projectile, the ring 61 of brass or other softmetal will be forced thereinto by the explosion sufficiently to holdsaid gas-check 61 upon the projectile during its flight, and by thismode of construction the said gas-check can be cast and finishedseparately from the projectile, and only requires to be driven upon thesaid polygonal projection c.

f is the percussion cylinder or sleeve, fitted to screw into the forwardend of the projectile, and carrying within it the percussion-nipplehammer g, as heretofore; but I form around the said hammer g a groove ati, receiving the point of the screw 70, so that the projectile mayrotate on starting before the hammer 9 coinmences to turn, the saidgroove '5 allowing of this movement without injury to the screw k.

I make use of two or more nipples or cones Z. I have shown three, andupon each of these cones a cap is to be placed, so that when themomentum of the shell is arrested by striking any object the inertia ofthe hammer 9 will cause it to go forward, cutting off the point of thescrew It", and, striking thepercussion-caps on the nipples 1 against theinner side of the screw-plug m, cause the explosion of the shell 5whereas in cases where only one nipple is employed a defect in the onepercussion-cap will I prevent the shell being exploded.

I have shown a short piece of wire, 12, introduced in a hole in thescrew-plug m and passing back against the face of the hammer g, toafiord additional security in transportation. This is to be removed byunscrewing the plug m previous to using the projectile.

It will be evident that if the screw k was introducedin such a positionthat its point came in front of the end of the hammer g the motion instarting would be allowed for, as before mentioned, or if the screw or across-pin was introduced in the back portion of the said hammer 9, sothat the end would project over the back end of the sleeve or cylinderf, the same effect would be attained.

I find that shells usuallyare not thick enough to withstand theconcussion in firing, as they very often break to pieces in the gun, andwhen made sufiiciently thick to obtain the necessary strength they arenot broken into many pieces by the explosion. I find practically thatwhen the area of the cavity is one-seventh or less of the area of theprojectile transversely the shell will not break in firing, and, inorder to cause the shall to break into small fragments when it explodes,I fill the same with gun-cotton or other explosive material morepowerful than gunpowder.

I do not claim the use of several percussioncaps in a projectile actingin different directions, according to the Way in which the projectilestrikes the object; but

What I claim, and desire to secure byLetters Patent, is

1. The mode herein specified of allowing the projectile to rotateWithout at first revolving JOHN F. SHEARMAN.

Witnesses THos. G120. HAROLD, CHAS. H. SMITH.

